Warren County Wildlife: Star-nosed moles can smell underwater

Warren County wildlife is just as amazing underground as it is above, because of the presence of a creature that is said to have the best sense of touch of any mammal in the world. With the use of it 22 fleshy pink tentacles on its nose to form a “star,” the star-nosed mole burrows its way underground searching for prey.

The star-nosed mole inhabits areas with moist soil and poor drainage, like mucky wetlands and the banks of streams and ponds. It's well suited for fast movement in the moist soils using its water repellent fur, cylindrical body and large claws to dig for small prey, such worms (including leeches), aquatic insects like dragonflies and damselflies, and the occasional terrestrial insect, mollusk, and even small fish.

The star-nosed mole is essentially blind and lives its life largely underground. So it relies on its tentacled star nose, which is covered by about 25,000 minute touch receptors, known as Eimer’s organs, to sense out prey objects. These receptors come in three varieties, including one that senses the microscopic texture of objects, believed to be unique to the mole. It has been documented that the tentacles can touch as many as 12 objects per second and are also reported to be able to detect the minute electrical fields produced by animals as they move through soil or water.

Additionally, the star-nosed mole blows and re-inhales air bubbles underwater about five to 10 times per second to track prey. Basically the mole aims its bubbles at specific targets; it'll blow out a bubble to touch the surface of an object, so when these bubbles come into contact with an object, it picks up odorant molecules that mix with the air and are drawn back into its nose when the bubble is inhaled.

That means that the mole uses the bubbles to smell. To date, the star-nose mole is the only mammal species known to use this bubble-blowing technique to smell, thus it is the only mammal species known to be able to smell underwater.

Star-nosed moles are currently relatively common, but the destruction of wetlands can have adverse affect their numbers.

This story is a weekly feature that runs with the cooperation of New Jersey Audubon. For more information about NJ Audubon or how to perform conservation efforts on your property, contact John Parke of NJ Audubon at john.parke@njaudubon.org or visit njaudubon.org